What do you mean exactly? Some people like being able to watch YouTube and Netflix without utilizing a third party device.
The tv also has a microprocessor to upscale/decode content. Most tvs also have the ability to connect to a variety of sound systems through Bluetooth.
If your concern is additional cost for the bundled features, I believe the ads subsidize and offset the cost. (I'm not pro ad. Again, I do not connect my tv to the Internet, but let's not reject the benefits entirely).
"Non smart" TVs are prohibitively expensive in my experience. They are large format monitors. You can also consider a projector.
I have yet to run into a TV that doesn't work entirely offline at any pricepoint